Real-Time Railway Crew Rescheduling: Performance Support with Explanations

Crew management in a railway company still relies on manual procedures, and users of crew rescheduling systems sometimes feel uncomfortable with a calculated schedule. One way to win a user's trust is by interactively explaining the reason(s) for the solution calculated by a computer. We thus propose a schema for describing crew rescheduling patterns in an 'if-then-because' format and propose an improved method for controlling user interaction based on the patterns. Use of this method improves not only the interaction between the system and its users, but also the interaction between the knowledge engineers and experts maintaining its rule base. An improved system developed using the proposed method generates crew schedules automatically by using a rule base comprising 30 patterns. System tests with an actual schedule for crews and trains in a railway line demonstrated that interactive processing with the help of an explaining function that visualizes the computing process is feasible at both the operational level and the task level.